# Record phonon interference enables label-free single-molecule detection

*Quantum vibrations just set a record — and they can flag a single molecule.*

Researchers at Rice University have tuned vibrations in a solid so precisely that a single molecule can be detected without fluorescent tags. They boosted interference between phonons — the quantised vibrations of a crystal — using a layered silver–graphene–silicon carbide structure. ([sciencedaily.com](https://www.sciencedaily.com/releases/2025/08/250814094658.htm?utm_source=chatgpt.com))

“**This interference is so sensitive that it can detect the presence of a single molecule**,” said first author Kunyan Zhang. The team says the approach could feed next‑generation sensors and quantum devices. ([sciencedaily.com](https://www.sciencedaily.com/releases/2025/08/250814094658.htm?utm_source=chatgpt.com))

## What’s new
The researchers report record-strength Fano resonance — about two orders of magnitude higher than previous reports — making the signal extremely responsive to small surface changes. ([sciencedaily.com](https://www.sciencedaily.com/releases/2025/08/250814094658.htm?utm_source=chatgpt.com))

## How it works
Using a method called confinement heteroepitaxy, they intercalated a few layers of silver atoms under graphene on silicon carbide, forming an atomically thin metal at the interface. Raman spectroscopy then showed an asymmetric line shape and, at times, a full dip known as an antiresonance — clear fingerprints of intense interference. ([sciencedaily.com](https://www.sciencedaily.com/releases/2025/08/250814094658.htm?utm_source=chatgpt.com))

## Why it matters
Add a single dye molecule to the surface and the spectrum shifts markedly, enabling label‑free single‑molecule detection with a simple, scalable setup. “**Compared to conventional sensors, our method offers high sensitivity without the need for special chemical labels**,” said corresponding author Shengxi Huang. ([sciencedaily.com](https://www.sciencedaily.com/releases/2025/08/250814094658.htm?utm_source=chatgpt.com))

## What’s next
Low‑temperature checks show the effect arises from phonons alone, not electrons, and it is absent in bulk metals; other 2D metals such as gallium or indium may be engineered to deliver similar effects. ([sciencedaily.com](https://www.sciencedaily.com/releases/2025/08/250814094658.htm?utm_source=chatgpt.com))

### Takeaway
By making vibrations interfere more strongly than ever, the team has turned the whisper of a single molecule into a readable signal — a step toward simpler, ultra‑sensitive sensors.

Read more in the original release on ScienceDaily: [Scientists just made vibrations so precise they can spot a single molecule](https://www.sciencedaily.com/releases/2025/08/250814094658.htm).